Self-cooling strain insulator



APPLICATION FILED DEC. I0, 1918- Patented Feb. 14 1922.

WITNESS UNITED STATES PATENT OFFICE.

LOTIIS STEINBERGER, 0F BROOKLYN, NEW YORK.

SELF-COOLING STRAIN INSULATOB.

Specification of Letters Patent.

. Patented Feb. 14, 1922.

Application filed December 10, 1918. Serial No. 266,050.

One of the objects of my invention there- I fore is to provide a selfcooling strain insulator provided with additional means for prolongingthe life of the insulator.

Another object is to provide a strain insulator, the strain members ofwhich are so arranged as to surround the ventilating conduit and alsosurround, the electrical conducting means situated in the centralportion of the insulator body.

Another object is to provide a strain in sulator provided with strainmembers embedded within the central portion thereof and arrangedadjacent to a metal lined condiiit passing through the central portionof the insulator.

Other objects will appear from the subjoined specification and claims.

Referring to the drawlngs;

Fig. 1 is a vertical section'through the central portion of my improvedinsulator,

embodying my invention, portions of the insulator being shown inelevation.

Fig. 2 is a section on line 2-2 of F 1.

It is well known that in actual operation the insulating material,especially at the central ortion of the insulator, becomes heatedlosesits eificiency. In other words, its efficiency is lowered, notonlyfrom an electrical standpoint but from a mechanical. standpoint aswell. If the heat is permitted to continue for a certain period of timethe destruction of the insulator will follow.

The present invention is applicable to all insulators but especially tostrain insulators and the insulator structure is so formed that thecentral portion thereof which heats rapidly, is provided with a metallined ventilating means, permitting passage Oi the cool flash overs orleakage and thereby the insulator air therethroughand the exit of thehot air, the metal lining forming a conducting path for flash overcurrent between the strain members.

It is desirable to keep the central portion of the insulator body whichis adjacent the strain members as cool as possible, other w se theinsulating material when heated Wlll so change in structure that thestrain members will gradually move towards each other, and it is obviousthat as they so move the electrical creased.

Referring to the drawings, in which the same reference characterindicates the same part in the several views:

A man insulator the body of which may be formed of any suitableinsulating material, but I prefer to use the insulating material wellknown in the art as electrose. B is the integral strain member made ofmetal and C is a two-part strain member also made of metal, which isprovided with the well known means for connecting the two partstogether, namely, one of the projecting ends 10 of the strain member isprovided with screw threads which engage the screw threads in the socket11 of the removable portion of the strain member. The sleeve 12 is screwthreaded to the other projecting end 10 of the embedded portion of thestrain member and to the abutting end 13 of the removable portion of thestrain member. This means of' connecting the two-part insulator so thatsaid parts may also be removed, is well known in the art and thereforeonly requires a general description. The body of insulating material isprotected from being broken by the integral flanges 15 and 16 on the legportions 17 and 18 of the embedded section of the two part strainmember;

The strain members are also. of the type invented by me and consist ofring shaped portions 20 and 30, said rings bridging the upright portionsrespectively of the two strain members. The body portion of theinsulator is molded about the strain members afterthey have beencentered with re bringing the ring value of the insulator is de-vLdially projecting-flange 50 extending from not shown in the drawing)these projections" abutting against-the flanges l5 and 16 above referredto, and llhQlG lS also a central, ra-

the insulator. v V p f V A central opening or conduit 60 is formedthrough the body of the insulator, said con-c duit continuing throughthe ring portions of the embedded strain members. In forming the conduitcarehas to be takento'providea suflic ent thickness of insulating material around the inner surfaces of the rings.

To illustrate, if the diameter of the cross sections of the ringportions'of" the strain member are each-'one-half inch, and the innerdiameters of the ri'ng'portions: are each one and one quarter inch, thediameter of the centralhole should be such that there will be left atvleast one-half inch thickness of insulating material around the interiorof the ring portions of the strain member.

The thickness ofjinsulating "material at these points is preferablyequal to the minimum thickness of insulating materiallaround the legportion ofthe strain member, as at the parts wfshown in the figure: f 7

"As v'villfbe seen, the centrally arranged hole passing throughthe bodyofthe insu-. lator and throughthe strainmembers per mits of the readyventilation of the insulator when it is inactual operation andconnec'tedto a line,';thereby tending to cool the central portion ofttheinsulator, thus: preventing"its destructionfby' the generated heati pThe tube 7 0, preferably brass,

isinserted in the conduit '60 and molded therein toform a metalliclining therefor.

As will bereadily understood the metallic tube" 701 does notnormallycarry any electric current at all. Should'however, the voltagebecome sufficiently high, itjwill break down theairbetween the terminalsorstrain' mem- V bers, and the ends of the tubelneares't there to. ilnother words, a path s provided for the jcurrent through the 'insulatorrather than around the insulaton therebyaffording protection totheinsulator.

The flashover, above referred tobetween the strain "members'and the endsof the metal tube; wilhoccur when the insulator is' in aperfect-condition. 7

' mediately-"surrounding the metal parts, and

these imperfections maybe magnified when theinsulatinfg' bodyb'ecomesheated while inuse; Should such'a condition exist and.

the voltagebecome sufliciently high the body the same andarc to theexposed strain members. 'Before the insulator could be totally destroyedit would have to puncture the insulating material at a different placefrom its firstpuncture and thereby go to ground and my invention isdesigned 'to prevent or m n mize the danger of th s ocg currence.

The relation of the amount of insulation material between the two" ringmembers 20 andSO to the amounts of insulating material between either ofthe rings20 or'30and the metal tube is such that'the current would seekthe metal tube ratherthan to puncture the insulating material atanyother 'poin t' as the electric current always seeks the l, c e

easiest path. a v 1 s v Owingto this construction in which theventilating conduit is metal lined the life of the in'sulator' ismaterially prolonged.

It is to be understoodthat the aboveldescriptionand drawings are merelyillustra tive and the invention is notto belimited" in any respect,exceptas defined in the sub? joined claims.

' Having now I claim as new and desire to secure by Letters Patent is: ii

1. A strain insulator including [an "insu-" ti e bo y p o i W h ne terng; strain gmemberspartially embedded therein, said insulator having a'metal linedjyentilatrl ing conduit extending therethrough," saiddescribed invention what conduit'passing "through the o ppositely posedembedded portions of thestra'in mam- 2', A;- iinsulaltor consisting ofbody ;of insulating pmateri'al, interlocking strain members embeddedtherein, said of in sulating materi'al being pi'oriderbwith ventilatingconduit passing therethrough, v

saidiconduit also passing through the central embedded, portions of the,strain members,v and a metal lining for said conduit;

3. Aninsulatm comprising a ;bojdy of n sulating material; strain memberspart, y

embedded therein, said body "of mad m material provided with'ganelctrica l J tubular conducting member passing'thei'e Q- Infpract1ce,-however, incipient flawsoir imperfegition's may sometimes bepresent in thecentral portion of the insulator body im'-- through, saidconducting member also passing through, the central embedded portions ofthe strain-members, j d 4'. An insulator, comprisingabody of in r asStilt fitti g materiahfstrain' members provid'etl with centrallyarranged bridge portions molded therein, saidinsulating body beingprovided with a ventilating metal lined con lat duit passingtherethrough and also through the centrally arranged bridge portions ofthe strain members.

5. In an insulator, a body of insulating material, interlocking 7 strainmembers molded therein, the central portions of the strain memberssituated opposite each other, the said central portions being ringshaped and a metal lined ventilating conduit passing through the body ofthe insulator and also through the ring portions of the strain members.

6. An insulator comprising a body of insulating material, interlockingstrain members molded therein, the central portions of the strainmembers situated opposite each other, the said central portions beingring shaped and an electrical conductor passing through the body of theinsulator and also through the ring portions of the strain members.

7. An insulator comprising a body of insulating material, strain membersprovided with centrally disposed portions assembled therein, said bodyof insulating material being provided with an electrical conductingmember passing therethrough, said conducting member passing through theembedded centrally disposed portions of the strain members.

8. An insulator comprising a body of insulating material, interlockingstrain members provided with centrally disposed portions molded therein,the central portions of the strain members situated opposite to eachother, the said central portions being ring shaped and an electricalconductor passing through the body of the insulator and also through thering portions of the strain member.

In witness whereof, I have hereunto set my hand at the borough ofManhattan, city and State of New York, this 27th day of November, 1918.

LOUIS STEINBERGER.

In presence of- ZITA M. GRAHAM.

